The present invention relates generally to devices for collecting and transporting biological samples, and particularly to a method and apparatus for preserving collecting and transporting evidentiary samples for analytical testing.
Some of the practical and evidentiary concerns associated with the design of devices for collecting and transporting biological samples are outlined in U.S. Pat. No. 4,873,193 which relates to a method and apparatus for the collection and transportation of biological specimens such as urine and similar biological substances.
Besides the evidentiary considerations for keeping the containers sealed and secure prior to use, there is the concern that the equipment used for blood sampling must be kept sterile to prevent contamination or the transfer of communicable diseases.
Conventionally, small blood samples for white blood cell counts were taken by pricking a finger of the patient and removing an aliquot of blood by pipette or capillary tube, and placing that sample on a microscope slide for inspection. More complicated testing requires taking a larger sample, which was traditionally performed using a pipetting catheter. The donation of large blood samples on the order of one pint for use in transfusions or blood component separation is normally accomplished using a larger vein puncturing cannula and sterile catheter and bag assembly familiar to the art. More recently, complex machines which separate blood components and extract only certain elements, such as platelets or leukocytes, and which return the remainder of the fluid blood components to the patient have been developed. These machines generally operate on the principal of centrifugal elutriation or one of various filtration methods, such as shown in U.S. Pat. No. 4,680,025.
Sampling blood for evidentiary purposes present some particular problems not addressed by these conventional devices. Several are useful only for micro-samples, and two individual samples of moderate size are generally required for evidentiary purposes, one for presumptive testing and a spare for alternate or backup use. The more complicated machines or larger catheters can be used to take moderate sized samples, but are either very expensive, not mobile, or do not provide for the storage and transportation of individual samples in a manner suitable for analytical testing or evidentiary use. Moreover, none of the existing devices satisfy the legal and evidentiary requirements for maintaining a valid chain of custody from prior to sampling until testing.
Specialized devices for taking blood samples for testing are known to the art, representative examples being disclosed in U.S. Pat. Nos. 4,385,637 on a syringe-like blood sampler; 3,366,103 on a blood collecting assembly; 4,494,882 on a method and device for collecting, transporting, and delivering micro-samples of blood; 4,409,990 on a fluid sampling needle assembly and method of use thereof; 4,320,769 on a universal holder or blood collecting tubes; and 3,901,219 on a blood collecting container and method.
Of these types of devices, the most commonly utilized blood sampler is the assembly comprising a multi-sample needle, an evacuated blood sampling tube, and a holder for combining the two in an operable configuration. One such assembly is marketed under the name Vacutainer by the Becton, Dickinson and Company of New Jersey. Many patents disclosing improvements and modifications in such a device are known, representative examples of this type of a device being shown in U.S. Pat. Nos. 4,317,456 and 4,436,098. The improvements and modifications generally relate to vein entry indicators, anti-backflow valves, stopper configurations, and the like.
These devices generally do not address the problem of storing and transporting the contents of the sample vial, or of the device or assembly prior to sampling. Composite samples of distinct biological substances such as blood and urine raise distinct problems. Specimens such as urine are usually contained in larger receptacles, and care must be taken to prevent their breakage and to keep them from damaging the blood samples. The components conventionally used for blood sampling generally include such items as fragile glass vacuum tubes and syringe needles, which require greater care in handling and during transportation. As with any medical "sharp," care must also be taken to permit easy access to and use of the equipment, in order to prevent accidental injury to the medical personnel. A system for storing or transporting distinct samples must allow the person taking and handling the samples to keep track of and conveniently work with the samples and the sampling equipment, and to safely store and protect those components not being used.